The present disclosure relates generally to methods, optical telemetry systems, and fiber optic cables for providing optical pulses.
An optical telemetry system is sometimes deployed in a wellbore to facilitate optical communications with downhole tools and devices and for optical sensing of a downhole environment. In some embodiments, the optical telemetry system may include an optical source, fiber optic cables, optical sensors, and an optical receiver. Optical pulses emitted from the optical source travel through one or more optical fibers of the optical telemetry system, where the optical pulses are used to measure a downhole environment such as, but not limited to, the temperature, pressure, vibration, displacement, velocity, torque, acceleration, and other properties of the downhole environment. The optical pulses may also be used to transmit signals indicative of downhole measurements as well as signals indicative of other data obtained by downhole tools to the surface.
Wellbores are often several thousand feet deep and may extend horizontally for several miles. As such, optical pulses emitted from the source emitter may travel through several miles of optical fiber before reaching a region where measurements are made. However, as the optical pulses travel through the optical fibers, the optical pulses experience a signal intensity loss proportional to the distance traveled. Further, optical pulses emitted at the surface are power limited due to safety concerns.
The illustrated figures are only exemplary and are not intended to assert or imply any limitation with regard to the environment, architecture, design, or process in which different embodiments may be implemented.